#include <bits/stdc++.h>

using namespace std;

ifstream fin("dfs.in");
ofstream fout("dfs.out");

const int NMAX = 1e5 + 7;

vector<vector<int>> v(NMAX);
vector<bool> ok(NMAX, false);

void dfs(int nod)
{
    ok[nod] = true;
    for (auto it : v[nod])
        if (!ok[it])
            dfs(it);
}


int main()
{
    int n, m;
    fin >> n >> m;

    for(int i = 0; i < m; i++)
    {
        int x, y;
        fin >> x >> y;
        v[x].push_back(y);
        v[y].push_back(x);
    }

    int ans = 0;
    for(int i = 1; i <= n; i++)
    {
        if(ok[i] == false)
        {
            ans++;
            dfs(i);
        }
    }

    fout << ans;


    return 0;
}